Download (PPI) Therapy in Patients with Functional Dyspepsia

Dr akhondi
Dyspepsia
 Dyspepsia is a common symptom with an extensive
differential diagnosis and a heterogeneous
pathophysiology.
 It occurs in approximately 25 percent (range 13 to 40
percent) of the population each year, but most
affected people do not seek medical care.
 This topic review will provide an overview of functional (also referred to as
idiopathic or nonulcer) dyspepsia, the most common type of dyspepsia
encountered in primary care and gastroenterology practice .
Definition
An international committee of clinical investigators developed
the following revised definition (Rome III criteria) of functional
dyspepsia for research purposes, which can also be applied to
clinical practice :
One or more of:
 Bothersome postprandial fullness
 Early satiation
 Epigastric pain
 Epigastric burning
AND
 No evidence of structural disease (including at upper endoscopy)
that is likely to explain the symptoms.
 These criteria should be fulfilled for the last three
months with symptom onset at least six months before
diagnosis.
 Two subcategories (postprandial distress syndrome
and epigastric pain syndrome) were also recognized
but their main value lies currently in research.
Dyspepsia
Functional
Dyspepsia
Non-GI
Causes of Symptoms
(cardiac disease,
muscular pain, etc.)
Structural Dyspepsia
(GERD, PUD, pancreatic
disease, gallstones, etc.)
Symptoms of Functional Dyspepsia
Ulcer-like Dominant
Nocturnal
pain
Dysmotility-like Domina
Nausea
Localized Heartburn Bloating
epigastric
Early satiety
Retrosternal
burning
burning
Worse
Better
with food
with food
Major Causes of Dyspepsia
Williams 1988
1996
(n=1386)
Stanghellini 1996
Heikkinen
(n=1057)
(n=766)
% of Patients with
Diagnosis
60
50
40
30
20
10
0
Gastric Cancer
Peptic Ulcer
Esophagitis/
GERD
Functional
Dyspep
Alarm symptoms
In addition to age, the following "alarm symptoms"
•
•
•
•
•
•
•
•
raise the suspicion of gastric malignancy [12]:
Unintended weight loss
Persistent vomiting
Progressive dysphagia
Odynophagia
Anemia Hematemesis
Palpable abdominal mass or lymphadenopathy
Unexplained iron deficiency anemia
Persistent vomiting Family history of upper
gastrointestinal cancer Previous gastric surgery
Jaundice
Rome III
B. Functional Gastroduodenal
Disorders
• B1 Functional Dyspepsia
– B1a: postprandial distress syndrome
(PDS)
– B1b: epigastric pain syndrome (EPS)
 Dyspepsia has been classified according to the
characteristics of symptoms that predominate.
However, such classification systems do not reliably
correlate with underlying pathophysiologic
mechanisms .
Pathophysiology
 The pathophysiology of functional dyspepsia is
unclear. Research has focused upon the following
factors:
 Gastric motor function
 Visceral sensitivity
 Helicobacter pylori infection
 Psychosocial factors
Gastric motor function
 Normal gastrointestinal motor function is a complex
series of events that requires coordination of the
sympathetic and parasympathetic nervous systems,
neurons within the stomach and intestine, and the
smooth muscle cells of the gut.
 Abnormalities in this process can lead to a delay in
gastric emptying (gastroparesis), a disorder that is
characterized by complaints of nausea, vomiting, early
or easy satiety, bloating, and weight loss.
Gastric motor function
 Delayed gastric emptying has been found in
approximately 30 percent of patients complaining of
dyspepsia [ 4-6] . However, there is generally a poor
correlation between these entities.
 Antral hypomotility has been found in a similar
proportion of patients, but its relationship to
symptoms is also uncertain.
 Up to 10 percent of patients have fast gastric emptying,
which may also be associated with dyspepsia.
 The relationship between gastric motor function and
gastric volumes may be important.
 A study of 57 adults suggested that symptoms were
associated with low fasting gastric volume and faster
gastric emptying .
Pathogenesis &
Pathophysiology of Dyspepsia
• Behavioural factors
• Gastritis
• H. pylori infection
• Increased
visceral
perception
• Altered
motility
Gastric motor function
 Gastric compliance is lower in patients with functional
dyspepsia than in healthy controls .
 In one study, for example, postprandial gastric
accommodation was evaluated in 40 patients with
functional dyspepsia and 35 healthy controls .
 Impaired gastric accommodation was found in 40 percent
of patients with functional dyspepsia (compared to the
lower range observed in controls), and was associated with
early satiety and weight loss.
 Treatment with sumatriptan (a 5-hydroxytryptamine
agonist that causes fundus relaxation) restored gastric
accommodation and improved meal-induced satiety.
Mechanisms Underlying
Increased Sensory Perception
Reduced
descendin
g inhibition
Increase
d
sensory
Visceral sensitivity
 Enhanced visceral sensitivity or visceral hyperalgesia
refers to a lowered threshold for induction of pain by
gastric distension in the presence of normal gastric
compliance. Visceral hypersensitivity has been
consistently demonstrated in patients with functional
dyspepsia .
Visceral sensitivity
 In a representative study, for example, the sensorial
responses (on a 0 to 10 perception score) and the
gastric tone responses (by electronic barostat) to
either gastric accommodation or to cold stress were
measured in 20 patients with functional dyspepsia and
20 healthy controls [ 10] .
 The mechanical accommodation of the stomach to
gastric distention (compliance) was similar in patients
and controls (52 versus 57 mL/mmHg).
Visceral sensitivity
 However, isobaric gastric distention elicited more
upper abdominal discomfort in the patients with
dyspepsia (perception scores 4.7 versus 1.1).
 Similar findings were noted in another report in which
reduced perceptual thresholds or altered pain referral
were found in 20 of 23 patients (87 percent) with
functional dyspepsia compared to only 2 of 10 patients
(20 percent) with organic causes of dyspepsia.
Visceral sensitivity
 Patients with dyspepsia are also more sensitive to acid
infusion into the duodenal bulb (which produced
nausea and fewer duodenal pressure waves) compared
to controls . .
 Visceral hypersensitivity, which has also been
proposed as an etiologic factor in irritable bowel
syndrome, appears to occur independent of delayed
gastric emptying.
 In contrast, somatic sensitivity (as measured by
transcutaneous electrical stimulation of the hand) is
normal in these patients [ 14] .
Visceral sensitivity
 — . Patients with dyspepsia are also more sensitive to acid
infusion into the duodenal bulb (which produced nausea and
fewer duodenal pressure waves) compared to controls [ 12] .
 Visceral hypersensitivity, which has also been proposed as an
etiologic factor in irritable bowel syndrome, appears to occur
independent of delayed gastric emptying [ 13] . ( See
"Pathophysiology of irritable bowel syndrome"). In contrast,
somatic sensitivity (as measured by transcutaneous electrical
stimulation of the hand) is normal in these patients [ 14] .
 Both mechanoreceptor dysfunction (peripheral mechanism) and
aberrant processing of afferent input in the spinal cord or brain
(central mechanism) may play a role in the pathophysiology of
visceral hypersensitivity. The latter mechanism is supported by
the observation that sympathetic autonomic activity enhances
the perception of gut distension in normal subjects [ 15] .
Helicobacter pylori infection






Although a possible role for H. pylori infection in functional dyspepsia is suggested by
several potential pathogenic mechanisms, a clear association among these factors, H.
pylori, and functional dyspepsia has not been established.
H. pylori is a well known cause of chronic active gastritis. However, gastritis is probably
not the cause of symptoms in most patients with functional dyspepsia. A consistent link
between findings on endoscopy and dyspepsia has not been found [ 16] .
H. pylori may cause altered smooth muscle dysfunction due to the induction of an
inflammatory response or by the initiation of an antibody response [ 17] .
However, most studies have not found an association between H. pylori and abnormal
gastric motor function in patients with functional dyspepsia. In one report, for example,
the gastric function of 27 patients with functional dyspepsia and H. pylori infection was
compared to that of 38 uninfected patients with functional dyspepsia [18] . The gastric
emptying time was similar in both groups.
The inflammatory response induced by H. pylori may lower the discomfort threshold to
gastric distension by causing alterations in the enteric or central nervous system [ 17] .
However, visceral hypersensitivity did not appear to be important in at least one study
which found that H. pylori positive and negative patients with functional dyspepsia had
no difference in the perception of mechanically-induced gastric distension [ 19] .
In addition to these rather unconvincing findings, most studies have not been able to
establish a temporal relationship between H. pylori infection and
TREATMENT
 — Treatment of patients with functional dyspepsia is
controversial and often disappointing, a sharp contrast
to the therapy of peptic ulcer disease [ 40] . The goal is
to help patients accept, diminish, and cope with
symptoms rather then eliminate them [ 40] .
 Similar to patients with irritable bowel syndrome, the
most important aspects of the therapy of functional
dyspepsia include explanation, validation that the
symptoms are not imaginary, evaluation and
management of relevant psychosocial factors, and
dietary advice
 . Medications that might contribute to symptoms
(such as NSAIDs) should be substituted or
discontinued whenever possible.
 Drug therapy, which is based upon the putative
pathogenetic mechanisms described above, may help
some patients. Several systematic reviews
 Drug therapy, which is based upon the putative
pathogenetic mechanisms described above, may help
some patients. Several systematic reviews have
summarized treatment trials of pharmacologic therapy
for nonulcer dyspepsia [ 41-46] . One of the most
comprehensive summaries focused on 57 trials
comparing a variety of pharmacologic interventions [
42] .
The following conclusions were reached:
 Prokinetic agents were more effective than placebo
(relative risk reduction (RRR) of 50 percent, 95% CI 30 to
65 percent).
 H2 receptor antagonists were more effective than placebo
(RRR of 30 percent, 95% CI 4 to 48 percent).
 Proton pump inhibitors and bismuth salts were more
effective than placebo, but the benefits were of marginal
statistical significance.
 There was no statistically significant benefit from antacids,
bismuth, or sucralfate.
 A limitation of virtually all the treatment trials was their
short duration, calling for caution in accepting the benefits
in a disorder characterized by chronicity.
 Interpretation of drug trials is also complicated by the
heterogeneous nature of the syndrome, the possible
dissimilarity of statistical and clinical significance [ 47] ,
the possible inclusion of patients with gastroesophageal
reflux, which could respond to prokinetic agents or acid
suppression, and the uncertainty that the study patients
are representative of those cared for by primary care
physicians (by far the largest group).
 Proton pump inhibitors — Several studies have evaluated the efficacy of
proton pump inhibitors (PPIs) in nonulcer dyspepsia and at least two meta-
analyses have been performed that reached similar conclusions [ 48,49] . A
meta-analysis of seven studies (with a total of 3725 patients) found that PPIs
were significantly more effective than placebo for reducing symptoms (relative
risk reduction of about 10 percent, 95% CI 2.7-17.3 percent) [ 48] . In a stratified
analysis, efficacy was confined to patients with ulcer-like and reflux-like
symptoms, but not in those with dysmotility-like symptoms or unspecified
dyspepsia. The major problem with the trials is the possibility that patients
with GERD could have been misclassified as having dyspepsia.
 The largest study, which is one of the most methodologically rigorous, included
1262 patients who were randomly assigned to receive omeprazole (20 or 10 mg
daily) or placebo for four weeks [ 50] . Complete symptom relief was observed
significantly more often with both doses of omeprazole compared with placebo
(38 and 36 versus 28 percent, respectively). The benefit was greatest in those
with ulcer-like or reflux-like symptoms; there was no significant benefit in
patients with dysmotility-like symptoms. Similar conclusions were reached in
another large placebo-controlled trial [ 51] .
SUMMARY AND
RECOMMENDATIONS
 . The following summarizes an approach in patients who




have been diagnosed as having functional dyspepsia. ().
There is no drug that has consistently been proven to be
effective for functional dyspepsia.
We suggest patients be reassured and given dietary and
psychosocial advice as needed ( Grade 2C).
We suggest that patients who do not respond to the above
be given a trial of acid suppression ( Grade 2B).
The benefit of acid suppression may be greatest in those
who have reflux-like symptoms. We suggest a four- to
eight-week trial of a proton pump inhibitor.
SUMMARY AND
RECOMMENDATIONS
 H. pylori eradication benefits only a minority of
patients. Guidelines issued by the American
Gastroenterological Association and the American
College of Gastroenterology recommend H. pylori
eradication in patients with functional dyspepsia
emphasizing a possible short-term benefit (number
needed to treat around 17) and a possible long-term
benefit (guideline available at)
Meta-Analysis of 10 Randomized Controlled Trials of Proton Pump Inhibitor
(PPI) Therapy in Patients with Functional Dyspepsia
 . However, because of potential side effects of therapy, we
suggest the decision to eradicate H. pylori consider the
individual patient's clinical features, including response to other
therapy and psychological factors ( Grade 2B).
 Some patients may respond to an antidepressant drug. We
suggest an antidepressant trial for patients in whom PPI therapy
has failed, especially if there is insomnia, which might also
respond ( Grade 2C).
 We generally use a tricyclic antidepressant drug or trazadone,
starting with a low dose (eg, amitriptyline 10 mg at bedtime,
desipramine 25 mg at bedtime, or trazadone 25 mg at bedtime)
and increasing after a few days, usually to only two or three times
these doses.
 Prokinetics can occasionally help. However, access
to cisapride is highly restricted in the United States
and many other countries. Domperidone is not
marketed in the United States and metoclopramide
often causes side effects.
 We generally limit a trial of metoclopramide (5 to
10 mg three times daily one-half an hour before
meals and at night for about four weeks) to young
patients in whom other therapies have failed.
 Herbal therapies continue to be investigated; we do
not use them.